Amphiphilic block copolymers: From synthesis including living polymerization methods to applications in drug delivery

Controlled radical polymerization (CRP) is a useful tool for the synthesis of new polymeric materials with varying compositions, functionalities, and topologies capable of self-assembly into well-defined supramolecular structures. Controlled supramolecular assemblies of block copolymers (BCs) could lead to bioactive and biodegradable materials with extraordinary properties that could be used as targeted drug delivery scaffolds for biomedical applications. Loading and delivery of drugs to explicit areas of the human body using materials-based systems have been moving towards the forefront of biomedical research for the past few decades. The idea has arisen from our progressing knowledge of materials - for example, biocompatible nanomaterials that encapsulate drugs and respond to environmental stimuli, and biodegradable hydrogels with tunable drug release profiles. Physical aggregates of amphiphilic molecules, such as polymeric micelles have been considered as powerful nanocarriers in the dawning era of polymer therapeutics. Polymeric nanoparticles-based therapeutics due to their flexibility in structure and unique chemical properties have made a significant clinical impact and has resulted in the development of polymer-drug conjugates that could enable the delivery of therapeutic agents to their intended site of action in a spatiotemporal manner, which can further improve efficacy and reduce toxicity. An ideal drug delivery system must respond to physiological changes in such cases synthetic polymers which show environmentally responsive behavior is the need of the hour. Advances in the fields of CRP have led to the development of multifunctional polymeric nanoparticles with precise control over the individual polymer segments. This review focuses on some of the most important CRP techniques and some recent developments in the field of stimuli-responsive BC systems. We hope that this review will not just give enlightening knowledge to analysts in this field but also offer new insights and applications for the advancement of CRP.